Important Announcement


ChemIDplus is moving to PubChem in December 2022.
Please see the NLM Technical Bulletin article for more information.

Skip Navigation
ChemIDplus LiteBrowseAdvanced

Substance Name: Pembrolizumab [USAN:INN]
RN: 1374853-91-4


  • NCI: A humanized monoclonal immunoglobulin (Ig) G4 antibody directed against human cell surface receptor PD-1 (programmed death-1 or programmed cell death-1) with potential immune checkpoint inhibitory and antineoplastic activities. Upon administration, pembrolizumab binds to PD-1, an inhibitory signaling receptor expressed on the surface of activated T cells, and blocks the binding to and activation of PD-1 by its ligands, which results in the activation of T-cell-mediated immune responses against tumor cells. The ligands for PD-1 include programmed cell death ligand 1 (PD-L1), overexpressed on certain cancer cells, and programmed cell death ligand 2 (PD-L2), which is primarily expressed on APCs. Activated PD-1 negatively regulates T-cell activation and plays a key role in in tumor evasion from host immunity. (NCI Thesaurus)

Molecular Formula

  • C6504-H10004-N1716-O2036-S46

Classification Codes

  • Antineoplastic Agents
  • Antineoplastic Agents, Immunological
  • Antineoplastic, Immunomodulatory, Immunotherapy
  • Immune Checkpoint Inhibitors

Names and Synonyms

Name of Substance

  • Pembrolizumab [USAN:INN]


  • HSDB 8257
  • Immunoglobulin G4, anti-(human protein PDCD1 (programmed cell death 1)) (human-Mus musculus monoclonal heavy chain), disulfide with human-Mus musculus monoclonal light chain, dimer
  • Keytruda
  • Lambrolizumab
  • Merck 3475
  • MK 3475
  • MK-3475
  • Pembrolizumab
  • Sch 900475
  • SCH-900475

Systematic Name

  • Immunoglobulin G4, anti-(human programmed cell death 1); humanized mouse monoclonal (228-L-proline(H10-S>P))gamma 4 heavy chain (134-218')-disulfide with humanized mouse monoclonal kappa light chain dimer (226-226'':229-229'')-bisdisulfide

Registry Numbers

CAS Registry Number

  • 1374853-91-4


  • DPT0O3T46P

System Generated Number

  • 1374853914